Analysis of Middle Nubian Vessel-forming Technology Using Reflectance Transformation Imaging (RTI)

Reflectance Transformation Imaging (RTI) is a photographic technique used to generate digital surrogates of surfaces that can be viewed using virtual lighting coming from interactively set directions, enabling the close structural examination of objects under digital raking light. In this study, RTI was applied to Middle Nubian pottery from sites near the Second Nile Cataract that were excavated by the Scandinavian Joint Expedition to Sudanese Nubia in the early 1960s. The ceramic traditions under investigation are currently known as C-Group, Pan-Grave and Kerma. An overarching aim of the project is to assess the possibility of understanding the relationships between these groups through detailed analyses of their material traditions. Based on the hypothesis that technological traditions may be related to cultural heritage, RTI is applied in this study to observe morphological traces of ceramic vessel forming processes. Two technological groups were identified, one consistent with paddle-forming, and another consistent with hand-building on a mat-lined surface. These technological groups correspond very closely to cemetery distributions, which suggests that the different techniques may be specific to different potterymaking traditions. It is suggested that vessel forming-technology in the so-called C-Group tradition is distinct from that of the so-called Pan-Grave and Kerma traditions, and that the validity of the divisions between Nubian cultural groups should thus be further interrogated. IANSA 2021 ● XII/1 ● 19–35 Aaron M. de Souza, Martina Trognitz: Analysis of Middle Nubian Vessel-forming Technology Using Reflectance Transformation Imaging (RTI) 20 standard photographic processes (see chapter 4). It will be shown that careful observation of the surface features revealed by the RTI process can assist in identifying similarities or differences in pottery-making technologies that may in turn be linked to cultural heritage and traditions. 2. Research objective The goal of the analysis was to test hypotheses regarding ceramic vessel-forming technologies among the Middle Nubian cultures. It has previously been proposed that Nubian pottery was formed using either the coiling or slab-building method (Arnold, 1993, pp.33–36), or by using a percussive process such as paddle forming (Arnold, 1993, pp.17–20). Both of these methods have been cited as primary forming processes (i.e., the processes used to create the overall vessel shape), and it is likely that both slab building and paddle forming (see chapter 6.1) were employed for different types of vessels and perhaps even in combination (Nordström, 1972, pp.47–48; Williams, 1983, pp.29–36). RTI was employed on a group of Middle Nubian vessels selected from the Figure 1. Map of Egypt and Nubia showing the locations of the SJE concession and the sites from which samples were taken. Map by A. de Souza. 0 200 km